4 Reflections on Primitive Vegetation. 



have been, if they had been covered, and pressed beneath the 

 weight of a thick deposit of mineral substances, and then ex- 

 posed to a high temperature. In order to be convinced of 

 this, it is only necessary to observe the almost ligneous struc- 

 ture which coal sometimes exhibits; and to examine the 

 numerous remains of plants contained in the rocks which ac- 

 company it. 



But the study of the impressions of stems, leaves, and even 

 fruits, which are generally enclosed in such numbers in these 

 rocks, not only proves the vegetable origin of this substance, 

 but also leads us to determine the nature of the vegetables 

 which enter into its formation, and which, consequently, must 

 have then occupied the surface of the earth. Among these 

 vegetable impressions, the most frequent are occasioned by 

 the leaves of ferns ; but these ferns of the primitive world, are 

 not those now growing in our climates, for Europe does not 

 produce, at the present day, more than thirty or forty species, 

 while the same countries then nourished more than two hun- 

 dred, all much more allied to those which now grow between 

 the tropics, than to those of temperate climates. 



Besides these leaves of ferns, the same strata contain stems, 

 whose dimensions might be compared to those of the largest 

 trees of our forests, while, in their form, they are totally uu- 

 like them ; so that all the older naturalists, struck with this 

 difference, and wishing, nevertheless, to find an analogy be- 

 tween them and the vegetables of the present world, had re- 

 ferred them to the arborescent vegetables, which were but 

 little understood at that time, to the bamboos, and palms, or 

 those large species of Cactus, commonly known under the 

 name oicierge. 



But a more minute comparison between the trees of the 

 equinoctial regions, and these stems of the ancient world, is 

 sufficient to nullify these supposed relations, (founded only 

 upon a resemblance in their general aspect), which some had 

 wished to establish between them ; and a more attentive stu- 

 dy, either of these stems, or of the leaves which accompany 

 them, very soon shews that the vegetables which formed the 

 primitive forests, cannot be compared with any of the trees 

 which now exist on our globe. 



The arborescent ferns, which, by the elegance of their ap- 

 pearance, now form one of the principal ornaments of the equi- 

 noctial regions, are the only arborescent plants which we can 

 find among these remains of ancient vegetables ; and their 

 number is very small. 



As to the other fossil stems, the remains of the primitive 

 forests of the ancient world, it is amongst the most humble 



